Apparatus of various types have heretofore been proposed and used for collecting the flesh of fish as removed from the skin by grinding or mashing to obtain a material for processed fish products such as sausage, boiled fish paste, etc. For example, an apparatus of the following construction is known for collecting the flesh of fish.
This apparatus comprises a hollow flesh collecting roll having a multiplicity of flesh collecting holes in its peripheral wall and a material conveyor belt in pressing contact with the roll. Flesh pieces having the skin still attached thereto and obtained by removing opposite side flesh portions of fish bodies from the bone are fed between the roll and the belt while rotating the roll and driving the belt to separate the flesh portions from the skin by grinding and collect the flesh within the roll through the holes.
Generally the flesh of fish includes flesh of low quality adjacent to the skin and underlying flesh of good quality. The above collecting apparatus has the following drawbacks because it has only one collecting roll in pressing contact with the belt.
When the pressure between the collecting roll and the belt is increased to collect flesh in a high yield, flesh of good quality and flesh of low quality are collected at the same time, so that the flesh collected is not suited as a material for preparing processed fish products of high quality. However, if the pressure is decreased to obtain flesh of good quality only, flesh of good quality is partly left unremoved along with flesh of poor quality which remains as attached to the skin to result in a low yield, hence uneconomical.